


Bitten by a True Believer

by kermiethefrog



Category: Supernatural
Genre: Biting, Bottom Dean Winchester, Demon Blood Addict Sam Winchester, Demon Dean Winchester, M/M, Plot What Plot/Porn Without Plot, Set during season 10, Top Sam Winchester, just a little bit of hate-fucking
Language: English
Status: Completed
Published: 2018-06-01
Updated: 2018-06-01
Packaged: 2019-05-16 19:53:03
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,897
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14817828
Author URL: https://archiveofourown.org/users/kermiethefrog/pseuds/kermiethefrog
Summary: “C’mon, Sammy,” Dean says. Flashes him a wicked grin, charcoal-eyes. The way he spreads out on Sam’s mattress, bare and offering himself up like Holy fucking Communion, drums heat under Sam’s skin, and he’s never sure if it’s arousal or anger when he’s faced with the demon. “Show me a good time, big guy.”





	Bitten by a True Believer

**Author's Note:**

> written for [wincest writing challenge](http://wincestwritingchallenge.tumblr.com/) for may. prompt is biting kink. i sweated through half of this trying to get it done on time so hopefully all of the gratuitous smut makes up for the none-betaing.

“C’mon, _Sammy_ ,” Dean says. Flashes him a wicked grin, charcoal-eyes. The way he spreads out on Sam’s mattress, bare and offering himself up like Holy fucking Communion, drums heat under Sam’s skin, and he’s never sure if it’s arousal or anger when he’s faced with the demon. “Show me a good time, big guy.”

“Shut up,” Sam shoots back. Dean smirks again, the cold shine of sharp teeth, and the bed dips where Sam’s knee drops next to his brother’s hip. 

“You want me to be a little sweeter for you? Say shit like, _I love you so much, make love to me_?” he teases cruelly—they both know Dean, Sam’s Dean, has never said those words. They both know Sam’s Dean keeps his heart too close to his chest and in a vice grip that’ll never give up.

Sam’s never been able to hold Dean like this, and it makes him feel sick that he takes the chance while he can.

His hand comes over Dean’s mouth, pressing hard enough to shove his brother’s cheek against his pillow. “I said, _shut up_ ,” Sam grits out. He can feel Dean grin against his palm, and that irritates him more. It’s that growing anger that causes him to flip Dean over by the hips—he knows he has to be careful, his shoulder still in the healing process, but logic and reason tend to fly out the window when met with the trigger-happy coil of fury that fills up his ribcage. 

Dean throws him a dark look over his shoulder, grinning when Sam drags his teeth over the jutting shoulder blade. The flat of his tongue lathes over Dean’s sweat-salt skin, mouth watering at the phantom taste of copper that wants to live in his throat. Dean groans out a soft, exaggerated moan, and Sam pointedly ignores him in favor of pinning his brother down with the weight of his body, taking his time as he nips over Dean’s back.

“You don’t have to be gentle with me, Sammy,” Dean says, rolling his hips back into Sam’s crotch, and Sam bites out a moan around a mouthful of freckled skin. “You know how much this body can take.”

Sam does. Broken bones, dislocated shoulders, bullet wounds, suicide runs, gashes across soft flesh. Black-and-blue bruises spread out across Dean’s throat in the shape of Sam’s hands. Sam has seen it all.

His teeth sink in, and Dean hisses out.

Sam leaves a mirrored image indent over Dean’s other shoulder, blood drawing under the surface in pinprick-dotted red marks where his teeth had been. He drags his fingertips over the area, and the soft coo that Dean lets out sounds like a tiger being tamed, stretching out warmly under his hand. 

“Looks good?” Dean purrs, and Sam bites down on his lower lip to keep himself from answering.

It does. Dean always looks best like this, marked up and bruised, back arched and body wanting. 

He notches down Dean’s spine, leaving bite marks on the way. One, almost hard enough to break the skin, right at the peak of Dean’s ass leaves his brother shuddering out a breath. Sam drags his teeth along the curve of Dean’s ass, down to the sensitive skin of his thigh, and the moan that leaves Dean’s lips is wrecked and needy.

“Fuck, Sammy, you gonna do somethin’ about that, or are you just gonna tease me?” Dean shoots out, and Sam bites down on the back of Dean’s thigh as a warning. Dean’s breath stutters, and Sam sees his fingers twist in the sheets; it makes him smirk, self-satisfied, and his tongue lathes over the wound. 

“Calm down,” Sam commands. He mouths over the mark he’s made, admiring it for a moment before nipping up the other side. 

“I am fucking calm.”

Sam licks a sudden stripe over Dean’s hole, and Dean’s breath hitches. 

He edges one finger in, cruel as he pushes in a second beside it without hesitation. Dean lets out a strangled noise, fingers curling into the sheets, and his eyes shine black when he looks over his shoulder. “Be careful with the fucking merch, asshole,” Dean bites out, and Sam laps around the rim. 

“I thought I didn’t have to be careful?” Sam shoots back. He wriggles his fingers in, pushing in to the first knuckle, and Dean drops his head down into the pillow. “Didn’t realize you were going to tap out so soon.”

“I’m not.” His voice is muffled, and Sam scissors his fingers through the tightness, feels Dean clench down around them. “Just thought you wanted to treat me like a sweetheart. If you had told me you were into some rougher shit—” His tirade is interrupted with the twist of Sam’s fingers, and Dean hisses out again before continuing. “I would’ve let you hit me around a little, fought back a bit,” Dean says, mockingly sweet. “Let you get out all that anger, baby.”

“Shut up,” Sam says, tonguing into Dean’s ass before his teeth come down on the curve of one cheek.

“Or what, Sammy? You gonna make me?”

Dean keens out a moan when Sam curls his fingers, flexing them inside. “Yeah. M’gonna make you,” Sam warns, and that shuts Dean up.

He works Dean open an edge too-rough, an edge too-quick; Dean tries hard not to show it, but Sam can see the tremble in his thighs, how the muscles in them clench and unclench against Sam’s fingers and tongue. 

“I’m ready,” Dean gasps out, back arching when Sam’s got three fingers in deep, fucking him spit-wet and open. “I’m ready, fuck me, gimme that dick, Sammy.”

“You’re not,” Sam counters, twisting his fingers—Dean moans, head dropping momentarily before he drags it back up. Sam leans forward and mouths at the back of Dean’s neck, and his brother twists, shakily balancing on one palm as he grabs a handful of Sam’s hair.

“I’m fucking ready,” Dean says; Sam tilts his head away when Dean tries to kiss him. Dean growls in frustration and tightens his grip, tugging Sam’s head back as he whispers in his ear. “Fuck me, Sammy. Fuck your big brother.”

The heat that shoots through Sam is so strong that he wavers at the sound of the soft-lilted moan against the shell of his ear, and he pulls back, leaning in to fuck his tongue into Dean’s ass one last time before he climbs off the bed. He strips off his sweatpants, hooks his thumbs on the waistband of his boxers and shoves them down. Sam delivers a heavy-handed smack to Dean’s ass to get him in position; when Dean doesn’t move fast enough, Sam grips his brother’s hips and drags him up, slotting his dick up against Dean’s ass. He takes a moment to roll his cock against his brother—Dean’s so fucking responsive, too, always keening back for more—before he ducks his head and spits on Dean’s tongue-fucked open hole. He thumbs over it, pressing in to the knuckle, before spitting on his palm and stroking his cock to spread his saliva.

“Lube?” Dean asks.

Sam’s answer is the head of his cock sinking into Dean’s ass.

“Oh, _fuck_ ,” Dean hisses out through clenched teeth, and Sam reaches out to grip Dean’s shoulder, slowly guiding him back onto his dick. “Fucking—fuck, so big, Sammy.”

“You got a lot more to go,” Sam murmurs quietly, inching his cock in. “Gonna take it all, Dean?”

“Yes, fuck,” Dean gasps, falling onto his forearms. “Needed this fucking dick.”

He’s patient, letting Dean get adjusted to each inch until all nine are snug in his brother’s ass, his hip bones flush flat against Dean. Dean curls his toes—like this, when Dean is quiet and breathing hard, when he can pretend that there’s no demon riding his brother’s body, something tugs hard at his heart and refuses to let go. Sam bends down and presses a kiss to Dean’s shoulder, against a smattering of freckles sitting there.

Dean rocks back, needy, and Sam rolls his hips into his brother, intimate as he fucks in deep. He wants to stay buried there, so close it’s like their souls are merged, and he breathes in, throat tight and chest tighter.

“You gonna keep fucking me like a bitch or are you gonna give it to me?” Dean mocks.

It shatters the illusion. Sam clenches his jaw as he grabs a fistful of Dean’s hair, straightening up—his mouth tastes sulfur-ashen, now, where he’d been pressing it against the demon’s shoulder. He hates this thing that’s taken his brother’s form. He hates it, and yet—

Sam moves a hand on Dean’s hip, starting a quick pace, rough as he makes Dean take it. 

“Fuck, yes, fucking—harder, Sam, fuck me harder,” Dean moans out. Sam grits his teeth and shoves Dean’s cheek into the pillow, half-covering his mouth with his fingers. He rails in, brutal thrusts of his hips, and Dean’s eyes roll back. “Yes, fu—fuck,” he sobs out. His tongue licks out, mouth sucking Sam’s fingers in, and Sam fucks them back deep until Dean’s gagging on them.

“Gonna come on your little brother’s dick, Dean?” Sam asks, and Dean moans, choked out by Sam fingerfucking his throat. Sam removes his fingers just to smack Dean’s ass—Dean stutters on it, then throws him a wicked, half-threatening grin over his shoulder. Sam’s hand shoots out and shoves his brother’s head down again. “Fuck yourself on my cock, bitch.”

Dean growls into the pillow. “Let me up, then,” he bites out, even as he tries to push his hips back uselessly when Sam stills his movements. “I can’t fucking—let me up, asshole.” It’s the closest thing to a whine that Sam’s heard.

Sam straightens again, leaning back to allow Dean a little space; when Dean moves to pull away, Sam’s hand comes down hard in the center of his brother’s spine, stilling him. “Where do you think you’re going?” he asks, brows furrowing, and Dean glares over his shoulder again, stopped where he’s pushed up on his palms as far as his arms extend.

“I’m going to ride you,” Dean shoots back, and Sam grips Dean’s hips and slams into him at the same time that his other hand comes down on his ass. Dean lets out a trailing moan as an elbow buckles, fingers digging into the sheets. 

“I said fuck yourself on my cock, Dean,” Sam responds, “just like you are now. Try to make yourself come.”

Dean lets out a snarl, eyes flickering black. “You’re really pushing my fucking patience, Sammy.” It’s supposed to be a threat, but it’s hard for Sam to think of it as one when he keens out a low whine as Sam starts pulling out. 

“And what, do you think you get the prize for being a good boy?” Sam says back. He watches the tension coil in Dean’s shoulders—even as a demon, he still has his trigger words, the ones that push him to be just that inch more submissive. 

Sam waits.

Dean drops his head down and pushes his hips back, ass sitting flush against Sam’s hipbones, and lets out a long, low moan. 

“Fuck,” Sam curses, quiet and under his breath. His hand gentles over the back of Dean’s neck, and Dean pushes into it, whether he realizes it or not. He’s clumsy as he fucks himself back on Sam’s cock, managing a sloppy and unrhythmic pace, frustration tensing his back. It’s so fucking hot, but he knows it’s not getting Dean off, and his voice turns teasing. “C’mon, Dean, don’t you want to come?”

It’s an edge cruel. Dean snarls again, and Sam’s fingers dig into the bruising marks on his neck as a warning. “I can’t—just fuck me, you asshole,” Dean grits out. 

“Ask nicely.” It’s paired with another heavy-handed hit, his palm burning where it connects with Dean’s ass. 

“ _Fuck you_ ,” Dean spits, trying to push up. Sam forces him back down, face flush against the pillow. “Stop being a little bitch and fuck me!”

Sam pulls out, dick resting heavy and hard against his thigh. Dean muffles a whimper into the pillow and turns to glare at him for a moment before his eyes fall away—Sam swears he sees uncertainty in them. “Ask. Nicely.”

It’s a long moment of silence, and Sam doesn’t think Dean’s going to say anything. Then—

“Please,” Dean says finally, quiet and closed-off, and Sam’s throat grows impossibly tight at the words. Dean looks like he’s pained just saying it, like the wound to his pride is battling with the trembling in his legs. “Please, Sam. Fuck me.”

“Was that so hard?” Sam asks, and Dean lets out a low growl.

“Fucking bite me, bitch,” his brother snaps.

So he does. Sam flips Dean over, moving to kneel on the mattress, and hooks Dean’s legs over his shoulders; he turns his head and bites a new red mark above Dean’s knee, along the inside of his thigh. He curves his chest down and folds Dean nearly in half—Dean’s body doesn’t allow it, much, but the demon occupying it takes the pain and next-morning ache like a champ. Sam’s mouth closes over Dean’s throat, creating a red ring and indenting hardest where his canines sink in. 

“All the way, c’mon Sammy, you know you want to,” Dean breathes out, hand reaching out to grip a fistful of hair. Sam doesn’t, just sucks a dark mark into existence and moves to scrape his teeth along the crook of Dean’s neck. “Pussy.”

Sam’s answer is his cock burying deep into his brother’s fucked-out hole, punching a moan out of Dean’s wrecked throat.

His arms cage in Dean’s head, and the demon’s hands wrap around his wrists. Sam is slow to start, a luxurious rhythm that has Dean trying to roll into him. He digs his feet into the mattress for purchase and starts to pick up the pace, his head dropping—Dean growls out moans into his ear as Sam fucks him. 

“Kiss me,” Dean begs, and it’s so fucking needy that Sam feels his chest grow tight. Sam can’t help the derisive laugh that drags out of his throat. “Fuck you, Sam. Please, kiss me, please, I need it.”

Sam turns his head, beard scratching against Dean’s cheek, and groans into his brother’s lips. 

Dean’s hands move from his wrists to clasping behind his neck—Dean wraps his arms around Sam and drags him closer, pulling him onto his forearms as Dean moans hotly into his open mouth. “That’s right, baby, fuck me just like that, so fuckin’ good, Sammy,” Dean breathes out, eyes rolling back when Sam’s hips start smacking hard against his ass. “Gonna make me come, Sammy—fuck—“

Sam’s hand shifts, fingers wrapping around Dean’s throat and holding his jaw steady so he can pull back and watch his brother’s face—Dean lets out a choked-off groan, cock coming untouched and cum streaking up his chest. 

Cheeks red, lips redder—mouth popped open and exposing sharp, white teeth edged with his pink tongue—long lashes fluttering shut. Sam wonders if Dean looks like this every time he comes, or only when he’s black-eyed with a marred soul.

“Fuck,” Sam curses again, thumb hooking into Dean’s mouth, pressing against his teeth as he fucks into him. “Where do you want it, Dean, tell me—”

“Inside,” Dean growls out, tongue working around his thumb, “fucking give it to me, Sammy, fill me up.”

Sam does. Dean holds on tight as Sam comes in him, his head dropping and teeth biting down into the giving flesh of Dean’s throat as he fucks through his orgasm, hips stuttering. He collapses, crushing Dean under the weight of his body, before he rolls to the side, cock slipping out a mess. 

He wonders if Dean’s an after-sex cuddler like his demon counterpart is. Dean all-but spreads himself over Sam’s chest immediately, humming in a self-satisfied way. Dean’s tongue is lazy where he laps at the sweat pooling in the hollow of Sam’s throat. “Stop,” Sam says quietly. Dean casts him a dark look and flicks his tongue against Sam’s chin. Sam flinches away, brows furrowing. “Stop it.”

Dean reaches out, whip-quick, and holds Sam’s jaw in his hands—Sam tries to tug away, but all Dean does is stroke his fingers through Sam’s short-trimmed beard. Sam watches as his brother slowly offers his wrist to Sam’s lips, eyelids going low-lidded and almost-fond. Sam drops his gaze, breathes in deep; he can feel the need rushing under his skin, the blood sweet-smelling and rich underneath the paperthin skin. 

“C’mon, Sammy,” Dean murmurs, and Sam feels his resolve breaking. “Let me take care of you now. Make you big and strong. Don’t you want that?”

“Why are you doing this?” Sam asks, voice crackling around the edges. 

Dean raises an eyebrow, like Sam’s a four-year-old asking silly questions. “Because I love you, dumbass,” he answers without hesitation. Easiest thing in the world. Sam shuts his eyes and closes his mouth around Dean’s wrist.

Dean always gets littered with bite mark bruises by the time Sam’s done with him, purpling pretty in the shape of his teeth, but it’s over the tender skin of his wrist that Sam breaks hard enough to bleed.

He drinks.


End file.
